by Noah Diamond
Ah, what is it about
Manhattan? What makes this particular island so enchanting? Is it the boroughâ€™s
status as a cultural and economic center? Its unparalleled ethnic diversity?
The inspiring peaks of its epic towers? Well, maybe all of this has something
to do with it, but if you had to boil it down to essentials, what really makes Manhattan special is its
Thatâ€™s right, Operator â€“
geology. Surveying the city today, we behold what appears to be a manufactured
environment; itâ€™s hard to believe an indifferent thing like the planet Earth
could have any effect on it. But in fact, the single most important factor in
the evolution of the modern city is the Manhattan
schist â€“ the bedrock on which the island rests.
Manhattan schist is a
thick, reddish sediment, and perhaps the toughest bedrock in the world. At the
dawn of the skyscraper era, it was the incredible strength of the schist that
made tall buildings possible. In other cities, the distance one must dig down
is a function of the distance one wants to build up. Chicagoâ€™s 108-story Sears
Tower has a very deep basement with many levels, essential to anchor the
structure in the earth. But in Manhattan, where the bedrock is dense, the 102-story
Empire State Building is anchored by the island itself. Its basement is a mere
two stories deep.
But the schist doesnâ€™t
just hold the skyscrapers in place. In doing so, it makes possible the vast
underground component of the city, where subways, tunnels, and utilities have
only shallow basements to work around.
The schist also dictates,
to a surprising degree, the shape of the Manhattan skyline. An aerial view of
the city, or a long-distance view from the east or west, reveals that the
famous New York City skyscrapers are largely restricted to two specific areas â€“
the Lower Manhattan financial district, and midtown. These two parts of the
island are where the schist is thickest and strongest. So before a single
building was erected in Manhattan, the general contours of the skyline to come
were geologically ordained.
If you want to, you can see the Manhattan schist. There are
outcroppings of the rock, in its natural form, in Central Park and Inwood Hill
Park. The schist was also used in the construction of some Manhattan buildings in
the eighteenth and nineteenth centuries â€“ most notably St. Paulâ€™s Chapel, on
Broadway between Fulton and Vesey Streets. Completed in 1766, this is the
oldest public building in Manhattan, and one of very few surviving relics of the
colonial period. Its principal material â€“ thatâ€™s the stuff dreams are made of.